Optimization Of Scheduling And Routing Of Hierarchical Service Tasks

In the development of the society,the synchronous development of the service industry is particularly important.In this thesis,the inspection and authentication service(IAS)is taken as the research background.The IAS includes electrical testing,gas inspection,vehicle inspection and so on,they are provided to the related manufacturing or maintenance companies.The IAS concerns the service efficiency,timeliness and quality as well.In this paper,on the basis of analyzing the features of IAS operational business,the scheduling and routing problem of service groups and tasks is studied.The problem can be abstractly described as:each inspection group has one or more types of service qualifications,each site for services has one or more tasks of single type.It aims to assign the multi-type IAS task to the service groups of various qualification,so as to obtain the service execution plan with lower costs and higher customer satisfaction,called Task Assignment of Service Group(TASG for short)problem.The followings are the main works of the thesis:(1)Considering the problem of priority-oriented TASG with time window,i.e.the service tasks has time window property of service expected time.A mathematical model of integer programming is designed to optimize the operational cost and service satisfaction,subject to a set of constraints of service qualifications and task exclusions.The Cplex software is applied and a genetic algorithm is designed to solve the optimization problem.To analyze the model parameters,a dedicated generator of problem instances is designed.The simulated experiments with different parameters are conducted and testify the effectiveness of proposed model and algorithms.(2)Considering the effective improvement of repetitive operational the tasks in practice,a repetitive efficiency oriented TASG problem is studied.A mathematical model of integer programming is designed with balancing the operational costs and service satisfaction,subject to a set of problem depended constraints.The Cplex software and a designed genetic algorithm are applied to solve the model.Simulated problem instances are obtained by the designed generator,and are used to analyze the model parameters and testify the effectiveness of model and algorithms.The comparison with the previous TASG problem indicates that the previous one emphases the operational costs minimization,while the current one is close to the service satisfaction issue.(3)Furthermore,the hierarchy oriented TASG problem is studied,where the problem is decomposed to two levels.Firstly,the attributes of service tasks are processed and ranked with the technique for order preference by similarity to ideal solution and the K-means method,then are introduced into the problem modeling.The mathematical model of integer programming aims to optimize the operational costs and service satisfaction.The model is solved by Cplex and a designed genetic algorithm.Through the simulated experiments,in terms of operational costs and service satisfaction evaluation,this improved model is compared with the two previous models,which indicates the improved model can compromise their advantages and reduces the time consuming in solving problem.